Hardy spaces of the conjugate Beltrami equation

We study Hardy spaces of solutions to the conjugate Beltrami equation with Lipschitz coefficient on Dini-smooth simply connected planar domains, in the range of exponents $1<\infty$. We analyse their boundary behaviour and certain density properties of their traces. We derive on the way an analog of the Fatou theorem for the Dirichlet and Neumann problems associated with the equation ${div}(\sigma\nabla u)=0$ with $L^p$-boundary data

Le conseil vétérinaire à l'officine

CHATENAY M.-PARIS 11-BU Pharma. (920192101) / SudocSudocFranceF

Benchmarking Cryptographic Schemes for Securing Public Cloud Storages

Part 5: Making Things Safe (Security)International audienceMuch research has focused during the last years on the security and privacy concerns of public cloud storages. Cryptographic primitives are commonly used to ensure user data confidentiality, authenticity and integrity. Confidentiality has been addressed by the use of symmetric-key encryption algorithms, while integrity and authenticity have been achieved by using message authentication codes, secure hashes or digital signatures. The choice of a specific configuration for securing an untrusted cloud storage highly depends on the expected security level, the size and type of data to store and the access pattern to these data. In this work, we are interested in overcoming the lack of comprehensive comparison of the costs and effectiveness of cryptographic primitives for securing public cloud storage, and ease an informed choice between them based on target usage conditions. We describe the results of an independent experimental study of six cryptographic schemes, representative of the principal design alternatives. Our practical experience report reveals that the best scheme for a given situation, such as a write-heavy workload of mostly small files, is not necessarily the most appropriate for a different situation such as a read-only workload of large files. We identify the scheme characteristics that are correlated with these differences and discuss the pros and cons of each design. Our experimental framework and results are available in the open for use by the community

Composition operators on generalized Hardy spaces

Let $\Omega_1,\Omega_2\subset {\mathbb C}$ be bounded domains. Let $\phi:\Omega_1\rightarrow \Omega_2$ holomorphic in $\Omega_1$ and belonging to $W^{1,\infty}_{\Omega_2}(\Omega_1)$. We study the composition operators $f\mapsto f\circ\phi$ on generalized Hardy spaces on $\Omega_2$, recently considered in \cite{bfl, BLRR}. In particular, we provide necessary and/or sufficient conditions on $\phi$, depending on the geometry of the domains, ensuring that these operators are bounded, invertible, isometric or compact. Some of our results are new even for Hardy spaces of analytic functions

Structure et fonctionnement hydropédologique d'un petit bassin versant de savane humide

La caractérisation minéralogique et structurale de la couverture pédologique a révélé la présence de deux grands domaines d'altération et de pédogenèse (domaine ferrallitique, domaine ferrugineux et hydromorphe) et de cinq systèmes (systèmes sol rouge, système cuirassé, système de dégradation superficielle, système hydromorphe, système colluvio-alluvial). L'étude des interactions avec les autres composantes du milieu physique fait apparaître l'influence de la lithologie sur le développement vertical et latéral des systèmes. Elle révèle l'existence de deux types d'érosion (érosion interne, érosion mécanique superficielle) qui se relayent et façonnent les différentes facettes du modelé. Enfin, elle établit un rapprochement entre deux formes de dégradation affectant la partie supérieure de la couverture pédologique (micro-organisations pelliculaire superficielles, système de dégradation superficielle). (Résumé d'auteur

Evolution of atmospheric lead over the northwestern Mediterranean between 1986 and 1992

International audienc

Switchable Lipid Provides pH-Sensitive Properties to Lipid and Hybrid Polymer/Lipid Membranes

Blending amphiphilic copolymers and lipids constitutes a novel approach to combine the advantages of polymersomes and liposomes into a new single hybrid membrane. Efforts have been made to design stimuli-responsive vesicles, in which the membrane’s dynamic is modulated by specific triggers. In this investigation, we proposed the design of pH-responsive hybrid vesicles formulated with poly(dimethylsiloxane)-block-poly(ethylene oxide) backbone (PDMS36-b-PEO23) and cationic switchable lipid (CSL). The latter undergoes a pH-triggered conformational change and induces membrane destabilization. Using confocal imaging and DLS measurements, we interrogated the structural changes in CSL-doped lipid and hybrid polymer/lipid unilamellar vesicles at the micro- and nanometric scale, respectively. Both switchable giant unilamellar lipid vesicles (GUV) and hybrid polymer/lipid unilamellar vesicles (GHUV) presented dynamic morphological changes, including protrusions and fission upon acidification. At the submicron scale, scattered intensity decreased for both switchable large unilamellar vesicles (LUV) and hybrid vesicles (LHUV) under acidic pH. Finally, monitoring the fluorescence leakage of encapsulated calcein, we attested that CSL increased the permeability of GUV and GHUV in a pH-specific fashion. Altogether, these results show that switchable lipids provide a pH-sensitive behavior to hybrid polymer/lipid vesicles that could be exploited for the triggered release of drugs, cell biomimicry studies, or as bioinspired micro/nanoreactors